AB0975 Minimal Clinically Important Difference of Total Knee Artroplasty Patient-Reported Outcome Measures
Authors: K. S. Kacmaz, T. Ünver, B. Unver
Journal: Annals of the Rheumatic Diseases (2022)

Background Total knee arthroplasty (TKA) is one of the commonest operations performed for end-stage osteoarthritis. Patient-reported outcome scales (PROMs) are optimal measures of the patient’ aspects of their current condition and response to treatment. However, a statistically significant change does not always mean or create an effect that clinically meaningful. Clinicians can use a greater change than minimal clinically important difference (MCID) value as a meaningful change in patients with TKA [1]. Nevertheless, there are variations in MCID values in studies analyzing the same outcome measures or patient populations. Objectives The aim of this study is to create a global summary of literature of the MCID for PROMs for TKA. Methods A comprehensive literature search administered using PubMed database from their years of inception to January 2022. Original articles calculating MCID of PROMs for TKA were identified, and the full texts of these publications, as well as their bibliographies were reviewed. Keywords included “outcome scale,” “TKA,” and “MCID.” Results This review examined 43 studies, in which 15 different outcome scales were administered to patients with TKA. MCIDs of the PROMs had distinct value or measurement process depending on the patients and clinical context. Distribution-based and anchor-based approaches were the most commonly used methods for calculating MCID. According to the analysis’; the WOMAC, KOOS, SF-12 and KSS were the most commonly used scales and there were so little research regarding the MCID of outcome instruments for TKA. Conclusion The reporting of outcomes in TKA were traditionally focused on implant survivorship and objective outcomes such as radiographic alignment, range of motion and, knee stability. However, patients and clinicans can have different perceptions of outcome, especially in the domains of subjective quality of life [2]. Therefore, it is recommended to use a combination of both objective and subjective measures to assess outcomes after TKA. In general, a wide range of MCID values was observed according to the scales. This can be due to the heterogenity in patient’ clinical conditions recruited for the studies. Apart from the differences, MCIDs of the Oxford Knee Score and KOOS were lower than the WOMAC score therefore we can interpret that they are more sensitive as an outcome scale. However, the MCID values must be interpreted in light of all variables, including the participants which were administered to. Each method for determining MCID has advantages and disadvantages, and the best way to calculate an MCID is to combine the results of both methods. The MCID is not flawless in detecting a clinically significant change, as sensitivity and specificity play a role. References [1]Tubach F, Ravaud P, Beaton D et al. Minimal clinically important improvement and patient acceptable symptom state for subjective outcome measures in rheumatic disorders. 2007; 34: 1188-1193. [2]Zacharia B, Paul M, Thanveeruddin Sherule M. Patient-based outcome analysis is important to determine the success of total knee arthroplasty: result of a focus group discussion. Med Devices (Auckl) 2016; 9: 125-130. Disclosure of Interests None declared